The Christchurch City Council is ready to face the consequences and Christchurch Mayor Bob Parker has apologised for its role in signing off the Canterbury Television (CTV) building.

A royal commission report released on Monday found that the six-storey building, which collapsed in the February 2011 earthquake, killing 115 people, should not have been granted a building permit by the council.

Parker yesterday apologised for council's "shortcomings" in 1986.

"It is clear, based on the evidence we have seen, there were shortcomings in those processes, but they were also one part of a very complex process that involved a number of other parties," he said.

"Naturally, everybody here is truly sorry. Albeit it's in a historic context, but it doesn't lessen the pain for us at this time."

Building and Construction Minister Maurice Williamson said yesterday 115 lives could not be lost and "somebody not be held to account".

Parker said he "absolutely agreed", even if the spotlight was shone on the council.

"If we need to stand up, be accountable in areas where we can be, then so we should," he said.

"Should there be an consequences of that, then so be it.

"That is what needs to be done in this case. We're all united on that."

He noted his staff had apologised at the commission's hearings earlier this year.

Parker also said the council's consent processes had improved in the past 26 years and were "completely different".

"We accept that the council of the time and the processes that it had in place were inadequate, or proved inadequate in this case, to ensure the appropriate checks and balances that were required were in place," he said.

"This organisation some years ago put in place systems that supersede that."

Council resource consents and building policy manager Steve McCarthy said multi-storey designs were now fully reviewed and peer-reviewed before consents were issued.

A national review of buildings with design structures similar to CTV was under way. Six Christchurch buildings, all unoccupied, had been reviewed.

"We've alerted the owners to the issue and prior to occupation they will be providing us with information to make sure those buildings are safe," he said.

Alan Reay-designed buildings had been reviewed by the council but they were not being specifically targeted, McCarthy said.

Reay is the principal of the firm that designed the CTV building.

"Where we've identified or suspect problems, we've investigated those in line with what the Government has directed us to do, but we won't be particularly picking on Alan Reay's buildings."

Many had been demolished, including Landsborough House in Durham St, McCarthy said.

Reay's work included "six or seven" multi-level buildings built between 1980 and 1990.

Council legal representative Kelvin Reid said any legal issues would be dealt with as they arose.

"If there is legal action taken, the council will need to consider what that is and respond to it accordingly," he said.

CTV PROSECUTIONS 'DIFFICULT'

Meanwhile, securing a conviction against those involved in building and designing the CTV building is unlikely, legal experts say.

Police have said they will investigate the findings of the Canterbury earthquakes royal commission on the disaster and consider laying charges.

Some survivors and families of the 115 people killed in the tragedy called for prosecutions and compensation after it was found the building had design and construction flaws that contributed to its collapse, and should not have been issued a building permit.

Christchurch lawyer Nigel Hampton, QC, said pinning those faults to individuals would be difficult.

"You'd have to choose your individuals with some care. You'd have to show gross negligence on their part and be able to prove that beyond reasonable doubt.

"You've got to show that . . . was an actual cause of the collapse of the building causing death."

Auckland University law professor Bill Hodge said it would be a tough case to pursue, but that may not be an issue for the police.

"[The police] know the public feeling and the depth of feeling. . . [they] may feel it's their role to provide a day in court for those people [and let] the courts decide."

Hodge believed police attention would likely focus on Alan Reay as principal of the company that designed the CTV building. "We're talking about the most serious stuff in the book. I guarantee somebody is looking at [it] right now."

Reay in July told the royal commission his firm was "ultimately responsible" if design flaws were found to be the reason for the collapse.

David Harding, the man who designed the CTV building and who commissioners found was unknowingly out of his depth, would warrant less attention, Hodge said. "If he didn't know that he should have known then it's not sufficiently serious to get him into that ballpark."

Lesser charges could include criminal nuisance, he said.

The other possible target was the Christchurch City Council, but both men agreed any action would be difficult with no corporate manslaughter charge in New Zealand.

Civil action would be equally hard.

The criteria and process to win such a case was rigorous, Hodge said, and families and survivors should "think very, very carefully" before pursuing it.

Hampton said: "I think they've got some problems.

"You've really got to show a gross malfeasance in the execution of a public duty and that's a pretty high standard."

Reay declined to comment on the findings or the police investigation. He had still not received a hard copy of the report, and it would be some time before he could comment on it.

Harding's lawyer, Michael Kirkland, said it was too early for his client to comment.